Liquid fuel injection system for multicylinder internal - combustion engines



- Aug. 22, 1944. w. von

-LIQUID FUEL INJECTION SYSTEM FOR MULTICYLINDER INTERNAh-COMBUSTION ENGINES K Filed July 5l, 1940 /n venfor Patented Aug. 22, 1944 LIQUID FUEL INJECTION SYSTEM FOR MULTICYLINDER INTERNAL COMBUS- TIoN ENGINES Willy Voit, Stuttgart, Germany; vested in the Alien Property Custodian Application July 31, 1940, serial No. 348,782

In Germany August 21, 1939 s claims. (ci. 29e-107.4)

This invention relates to an injection system for multicylinder internal combustion engines in which the distribution of fuel is electromagnetically control1ed. Y

In engines of this class an injection pump can 5 be adjusted to deliverdifferent amountsof-fuel to a pressure piping common toa plurality of injection nozzles, and the fuel passes from this piping through one of the nozzles, successively electromagneticallycontrolled by a distributor, into the associated cylinder.

According to the invention, the distributor preselects a nozzle independently of the amount to be injected, and this nozzle is kept; open by its associated magnet at least during the injecting period.

Two embodiments of the invention are illustrated in the accompanying drawing, in which `Figure 1 is a diagrammatic view of the total arrangement of an injection system according to the invention in an internal combustion engine;

Fig. 2 is a view of a slide valve arranged in the fuel supply piping;

, Fig. 3 is a wiring diagram of the electrical mem-I bers of the system; and I Fig. 4 is a view, partly in section, of an injection nozzle provided with locking means for the needle.

I designates a four cylinder four stroke cycle internal combustion engine whose crankshaft 2 drives an injection pump 3 by means of a pair of 30 gears 4 in such manner that the shaft 5 of the pump 3 rotates at half the speed of the crankshaft 2. A cam 6 disposed on the shaft 5 has four elevations, not shown, so that the :piston I, shown in broken lines, of the pump 3 carries out four 35 delivery strokes at each rotation of the shaft 5. The amount of fuel supplied at each stroke to a, pressure-piping 8 communicating with the pump outlet is regulated in known manner by the displacement of a rod l9. lThe piping 8 has branches 40 I is an electric distributor I2 whose revolving 45 finger I3 is driven from the pump shaft 5 and passes over four contacts I4 at each revolution. From each of these contacts I4 an electric conductor I5 leads to` one end of the winding of a ileld' coil I 6 provided in each shut-off member 50 II, the other end of the winding being earthed.

The shut-off member,clearly visible in Fig. 2,'

comprises a casing I1 made of magnetizable material and provided with a blind-bore I8 in which bore 20. A spring 22 tends to force the slide I9, also made of magnetizable material, upon the bottom of the blind bore I8. An extension of the bore I8 accommodates the coil I6 whose core 2| is firmly united with the slide I9. When current flows through the coil I6, its core 2I is lifted and the slide I9 firmly connected thereto passes into a position at which its cross-boreY 20 vis on a level witha continuous transverse bore of the casing I 1, with'which the branch of the pressure piping V8 interrupted by the shut-oil' member is in communication, so that fuel can enter the nozzle III connecting with the end of this branch.

'I'he circuit of each coil I6 controlled by the distributor I 2 is closed at least during the injecting period so as to permit the flow of fuel to each nozzle I0.

Fig. 3 indicates the connections and the control of the coils for the shut-oil' members of the various nozzles I0. The quantity and the beginning 24 is guided, and a spring ze tends to hold the' needle 24 in its closed position shown. Over the upper end of the needle 24 a pin 25 guided in the nozzle body 23 is pushed vertically to .the needle by a spring 28, and fuel entering at this position through a channel 21 in response to the pressure of the injection pump 3 is therefore unable to lift the needle 24. The other end ofthe pin 25 is placed in' a field coil 28. When lcurrent flows through the coil 28, the pin 25 acting as a magnet core is drawn into the coil against the vaction of the spring 26, and an impulse coming from the pump can now lift the' needle 24. The control of the current impulses for thecoils of each nozzle is eifected also by the distributor I2.

In the examples shown only one coil is excited, namely that whose nozzle is selected for injection, and the coils of the other' nozzles rema'in currentless. It is possible, however, to reverse conditions by utilizing the excitation of the coils for locking their associated nozzles and interrupting the ex-` citing current only for the coil through whose nozzle an injection i's to be made. 'In this case,

vthe consumption of current would, however, be

materially greater than in the constructions a slide valve I8 is guided possessing a transverse 55 shown. Y

cam surface adapted to cooperate with said caml portion to control the sliding oi' said valve needle from one extreme positionto the other thereby to controlthe discharge of fuel through said valve opening, and a solenoid-spring unit operatively associated with said cam pin to slide said pin between two extreme positions whereby the energization of the solenoid moves said cam pin to ..oneV

extreme position and the de-energization of the solenoid permits the spring to move the cam pin to the other extreme position.

2. A fuel injecting unit as described in claim 1 wherein said valve needle has its axis coincident with the axis of said cylindrical member and wherein said cam pin has its axis extending radially with respect to the axis ot 4said valve needle,

a spring operating to move said valve needle' toward its position closing said valve opening, said valve needle having adjacent said valve opening a surface which is subjected to the pressure of the fuel whereby a force is exerted against the action of said spring thereby to tend to move said valve needle away from said valve opening.

3. In an injection valve construction of the character described, the combination of, a cylindrical member having at one end a valve opening,

va. valve needle slidably mounted in said cylindrical member to move axially to and from a position closing said valve opening, said valve needle carrying a cam portion, a cam pin slidably mounted and positioned radially with respect to the axis of said valve needle and adapted to cooperate with said cam portion to control the sliding of said valve needle from one extreme position to the other thereby to control the discharge of fuel through said valve opening, a spring operative to move said valve needle toward its position closing said valve opening, said valve needle having adjacent said valve opening a surface substantially transverse to the axis of the valve needle which is subjected to the pressure of the fuel whereby a force is exerted against the action of said spring thereby to tend to move said valve needle away from said valve opening, and a solenoid-spring unit operatively associated with said cam pin to slide said cam pin between two extreme positions whereby` the energization of said solenoid moves said cam pin to one extreme position and the deenergization of the solenoid permits the spring to move the cam pin to the other extreme position. WILLY VOIT. 

